How to pass a variable from a test to another test

[aMillionTears]

I write a test class, it has two test methods. What I want to do is, at the first test I'd like to get some result and assign to a variable; and at the second test I want to do some test depend on this variable. What's the best way to do this? Currently, I use a "global", and I know I can put these two tests into a same method. But I look forward a better solution.

Thanks for submitting an issue!

Here's a quick checklist in what to include:

• Include a detailed description of the bug or suggestion
• pip list of the virtual environment you are using
• pytest and operating system versions
• Minimal example if possible

[pytestbot]

GitMate.io thinks possibly related issues are #2472 (Passing global variable from test function), #3118 (How can I use global variables through tests?), #1694 (Add possibility to pass parameter to the fixture from another fixture), #288 (Pass test result to finalizer for cleaning up debug data), and #153 (test intents).

[rachel1792]

Your first 'test' doesn't sound like a test. Does it include any assert statements?

Instead, you can make it a helper method to compute the value you need for your second test, and call that helper method in your second test. Just take of the test prefix or postfix from its name and pytest won't treat it as a test. Hope that helps!

[aMillionTears]

@rachel1792
My first 'test' is a test. The scenario likes this:
First, I want to test 'Create an item', and return the item's Id.
Then, I want to test 'Edit this item', and I should give this item_id to the test telling it which item to edit.
So, I need to collect first test's data, then give the data to next test.

[nicoddemus]

@zzyGit that's not possible without some ugly hack, but unittests are supposed to be idempotent and independent from each other. You should be able to run tests in any other.

But @rachel1792's advice is sound, why don't you create a fixture or method which creates the id for you? If the fixture fails for any reason, you will still get an error.

Another strategy is using something like:

@pytest.fixture
def item():
    return Item()

def test_item_created(item):
    # ensure item was created successfully
    assert item.value == 'something expected'

def test_edit_item(item):
    # ensure item is edited successfully
    item.edit()

[nicoddemus]

Closing as this has not seen activity in awhile.

[alexandru-cleverbase]

1. Create a class in conftest.py and import it in your test module. To protect yourself from errors caused by failed testcases that were suppose to add values in the class, assign None to all the known values.
   conftest.py:

class ValueStorage:
    value1 = None
    value2 = None

test_mytest.py:

from conftest import ValueStorage

def test_one():
    ValueStorage.value1 = "anything you want here"
def test_two():
    assert ValueStorage.value1 == "anything you want here"
    ValueStorage.value2 = ValueStorage.value1

class TestClass:
    def test_three(self):
        assert ValueStorage.value1 == ValueStorage.value2

You can pass dictionaries and lists and anything you feel like. If you require persistence (want the values to be kept from one run to another you can write them in a json file or use the cache option)